Achilles tendon rupture

Summary

Achilles tendon ruptures commonly occur in athletic individuals in their 30s, 40s, and early 50s while performing activities that require sudden acceleration or changes in direction (ex. basketball, tennis, etc.). Patients usually describe a sharp pain in their heel region almost as if they were “struck in the back of the leg”. The diagnosis of an acute Achilles tendon rupture is made on clinical examination as x-rays will reveal the ankle bones to be normal. The Achilles is the largest and strongest tendon in the body (figure 1). It is subject to 2-3 times body weight during normal walking so regaining normal Achilles tendon function is critical. Achilles tendon ruptures can be successfully treated non-operatively, or operatively –but they must be formally treated. Recent studies suggest that non-surgical and surgical treatment of Achilles tendon ruptures produce equivalent results. Surgical treatment may lead to a slightly faster recovery and a lower rate of re-rupture. However, surgery can be associated with very serious complications such as an infection or wound healing problems. For this reason non-operative treatment may be preferable in many individuals, especially those patients with diabetes, vascular disease, and those who are long-term smokers.

Figure 1: Achilles Tendon

Clinical Presentation

The Achilles tendon is the largest and strongest tendon in the body (Figure 1). It functions to help control the foot when walking and running. Ruptures of the Achilles tendon commonly occur in individuals in their 30s, 40s, and early 50s. This age group is affected because these patients are still quite active, but over time their tendons tend to become stiffer and gradually weaken. These ruptures usually occur when an athlete loads the Achilles in preparation to pushing off. This can occur when suddenly changing directions, starting to run, or preparing to jump (Figure 2). These ruptures occur because the calf muscle generates tremendous force through the Achilles tendon in the process of propelling the body. Patients will feel a sharp intense pain in the back of their heel. Patients often initially think that they were “struck in the back of the heel” and then realize that there was no one around them. After the injury, patients will have some swelling. If they can walk at all, it will be with a marked limp. It is very rare that a rupture of the Achilles is partial. However, a painful Achilles tendonitis or a partial rupture of the calf muscle (gastrocnemius) as it inserts into the Achilles can also cause pain in this area. The pain of an Achilles rupture can subside quickly and this injury may be misdiagnosed in the Emergency Department as a sprain.

Figure 3: Achilles Maximum Load during walking – Heel Rise

Physical Examination

The diagnosis of an Achilles tendon rupture is made entirely on physical examination. Often, there is a substantial defect in the Achilles 2-5 cm before it inserts into the heel bone. However, the main test is to determine whether the Achilles has been ruptured is the Thompson test. This essentially involves placing the patient on their stomach and squeezing the calf muscle. If the Achilles is intact, the foot will rise [plantar flex]. If it is ruptured, the foot will not move and will tend to be in a lower lying position.

Some patients mistakenly believe the tendon is working if they can push the foot down, however, patients will usually be able to move the foot up and down while sitting because the other surrounding muscles and tendons are still intact. Trying to push up while standing and applying body weight to the foot will reveal the true weakness. It will be difficult or impossible for a patient to stand on their toes for any length of time if they have suffered an Achilles tendon rupture -this is called the STAMP test. Sensation and circulation to the foot and ankle will be normal. This is quite rare, occurring in only a small fraction of patients with Achilles injuries. Patients suffering this type of Achilles avulsion injury tend to be older with weaker bone.

Imaging Studies

Plain x-rays will be negative in patients who have suffered an Achilles tendon rupture unless the Achilles injury involves pulling off (avulsion) part of the heel bone (calcaneus). The rupture can be seen on ultrasound or MRI. However, these studies are not indicated for acute ruptures unless there is some uncertainty about the diagnosis. For chronic problems of the Achilles or ruptures that are old, an MRI may be very helpful.

Treatment

Achilles tendon ruptures can be treated non-operatively or operatively. Both of these treatment approaches have advantages and disadvantages. Recent studies suggest that non-surgical and surgical treatment of Achilles tendon ruptures produce equivalent results. However, the decision of how an Achilles tendon rupture should be treated needs to be based on each individual patient after the advantages and disadvantages of both treatment options have been reviewed. It is important to realize that while Achilles tendon ruptures can be treated either non-operatively or operatively, they must be treated. A neglected Achilles tendon rupture (i.e. one where the tendon ends are not kept opposed) will lead to marked problems of the leg in walking, which may eventually lead to other limb and joint problems. Furthermore, late reconstruction of non-treated Achilles tendon rupture is significantly more complex than timely treatment.

Non-Operative Treatment

Non-operative treatment of an Achilles tendon rupture consists of placing the foot in a downward position [equinus] and providing relative immobilization of the foot in this position until the Achilles has healed. This typically involves some type of stable bracing in a walker boot with a heel lift. More aggressive rehabilitation programs for patients undergoing non-operative treatment may allow for graduated weight-bearing in the early phase of the recovery, however, it is often 6 weeks before full weight bearing in a boot or brace is allowed. In general newer rehabilitation protocols allow for earlier movement of the healing tendon while protecting it from significant loads that would cause the healing tendon to disrupt or stretch out. It is very important that the status of the Achilles is monitored throughout non-operative treatment. This can be done by physical examination or via ultrasound. If there is evidence of gapping or non-healing, surgery may need to be considered.

Formal protocols have been developed to help optimize non-operative treatments and excellent results have been reported with these protocols. The focus of these treatments is to ensure that the Achilles rupture is in continuity and is healing in a satisfactory manner while at the same time preserving the function of the calf muscle.The primary advantage of non-operative treatment is that without an incision in this area, there are no problems with wound healing or infection. Wound infection following Achilles tendon surgery can be a devastating complication and therefore, for many patients, especially those patients with diabetes, vascular disease, and patients who are long-term smokers, non-operative treatment should be contemplated.The main disadvantage of non-operative treatment is that the recovery is probably a bit slower. On average, the main checkpoints of recovery occur 2-4 weeks quicker with operative treatment than with non-operative treatment. In addition, the re-rupture rate appears to be higher with some non-operative treatments. Re-rupture typically occurs 8-18 months after the original injury.

Operative Treatment

Operative treatment of Achilles tendon ruptures involves opening the skin and identifying the torn tendon. This is then sutured together to create a stable construct. This can be performed through a standard Achilles tendon repair technique or through a mini-incision technique (to read about the different types of techniques, look under “Procedure” in Achilles Tendon Repair). By suturing the torn tendon ends together, they maintain continuity and can be mobilized more quickly. However, it is critical to understand that the return to normal activities must wait until adequate healing of the tendon has occurred.The potential advantages of an open repair of the Achilles tendon include:

Faster recovery: Operative repair of an Achilles tendon rupture may allow for a slightly faster recovery.

Early Range of Motion: Patients are able to move the ankle earlier so it is easier to regain motion and the rehabilitation program can be more aggressive.

The main disadvantage of an open repair of the Achilles tendon rupture is the potential for a wound-healing problem which could lead to a deep infection that is difficult to eradicate, or a painful scar.

Rehabilitation of Achilles Tendon Ruptures

When compared to the traditional treatment of casting and immobilization for a minimum of 6 weeks a protocol of rehabilitation exercises (combined with specific instructions for weight bearing and bracing) leads to improved recovery whether the injury is treated with surgery or not.The outline for the exercises, bracing, and weight-bearing for the treatment of Achilles tendon ruptures is as follows (adapted from Willets et al, Journal of Bone and Joint Surgery (JBJS) 2011):

Week 0-2
The ankle is braced at 20 degrees of plantar flexion (or a 2 cm lift is placed under the heel in a boot-type brace). No weight is placed on the foot. In the case of surgery, a wound check will occur in this interval.

Week 2-4
The ankle remains braced in plantar flexion. Exercises begin, several times per day out of the brace. The exercises consist of gentle up and down motion of the ankle, taking care not to stretch the Achilles tendon past neutral (90 degrees). Also, inversion and eversion of the ankle is performed, again with the ankle in slight plantarflexion.

Week 4-6
Increased weight-bearing is permitted. The exercises continue as above, and the brace is still worn day and night.

Week 6-8
The heel lift is removed and brace wear continues. Exercises progress, with slow stretching of the tendon past 90 degrees. Some strengthening of the calf occurs with the addition of resistance exercises.

Week 8-12
The brace is gradually weaned, using crutches as needed. Range of motion, strength, and proprioception are gradually optimized.